Make the new GtkAction code work with PolicyKit-gnome's use of actions.

    Make the new GtkAction code work with PolicyKit-gnome's use of actions.

        * gtk/gtkaction.c (gtk_action_[un]block_activate_from): Block
        the action.

        * gtk/gtkcheckmenuitem.c (gtk_check_menu_item_activatable_reset):
        * gtk/gtktogglebutton. (gtk_toggle_button_activatable_reset):
        * gtk/gtktoggletoolbutton.c (gtk_toggle_tool_button_activatable_reset):
        Work with non-toggle actions without complaining.

        * gtk/gtktoolbutton.c (gtk_tool_button_activatable_update): Updating
        the icon-name should not remove the label.

        * gtk/gtkimagemenuitem.c (activatable_update_icon_name): Also
        update the image when the icon name is set to NULL.

svn path=/trunk/; revision=22290